Scratch

MoreGamesNow wrote:

Do you want help with velocity-based movement or making a sprite move along a pre-defined path?

I want to make my sprite move along a pre-defined path.

MoreGamesNow wrote:

AgentCNF wrote:

MoreGamesNow wrote:

Do you want help with velocity-based movement or making a sprite move along a pre-defined path?

I want to make my sprite move along a pre-defined path.

And how are you defining the path?  With a mathematical formula?

I don't know! Thats what I'm asking. How do I make a sprite move in a curved path?

Tbtemplex97 wrote:

you may want to use a quadratic formula, they make curved graphs

I don't know what that is. D:

MoreGamesNow wrote:

Essentially, a "curve" is defined by a mathematical function.  You can figure out the function a number of ways but the most popular way is probably this:

Choose three points for a sprite to pass through (beginning, middle, and end of the path).   Solve the equation (y position) = a(x position)^2 + b(x position) + c using the three points.  In other words, if the first point is (3,5), one of your equations is 5 = a(3^2) + b(3) + c.  If the middle point is (6,3), your second equation is 3=a(6^2)+b(6)+c

Once you have your three equations you can solve for variables a, b, and c  (Do you know algebra?  If you have difficulty solving for three variables using three equations, I may be able to find a generic formula for the variables based on the three points).

Now you have y=3(x^2)-5(x)+3 (for example).  Now you have a path that your sprite can move along.  Just make the y position a function of the x position:

when gf clicked
forever
change x by (1)
set y to ((((3)*((x position)*(x position)))-((5)*(x position)))+(3))

I hope that made sense 

I don't understand that at all, cause im in 7th grade, so I don't know a whole lot of algebra. Instead of that, can you tell me if there's a way for me to draw a path and my sprite go along the path that I made? That may be easier... I don't know.

Last edited by AgentCNF (2013-01-22 16:28:42)

MoreGamesNow wrote:

Like this or with an invisible curve?

Preferably invisible. But I don't want people playing to draw it. I want to draw it in the studio and then when something happens, it moves along the line. like this:

when [space v] key pressed
forever
 follow line
end